Automatic gas bleeder igniter



June 2, 1959 l.. M. RIPPLE AUTOMATIC GAS BLEEDER IGNITER 2 Sheets-Sheet1 Filed March 24, 1954 INVENTOR. Ew/5 M. /Q/ppLE- June 2, 1959 L. M.RIPPLE 2,888,981

AUTOMATIC GAS BLEEDER IGNITER Filed Maron 24, 1954 2 shears-snm 2Ulf/agr 32 INVENTOR.

Lew/s M. Q/ppLe BY United States Patent C AUTOMATIC GAS BLEEDER IGNITERLewis M. Ripple, Cleveland, Ohio, assgnor to Republic Steel Corporation,Cleveland, Ohio, a corporation of New `lersey Application March 24,1954, Serial No. 418,411

2 Claims. (Cl. ISS-123) This invention relates to gas igniters and moreparticularly to an improved automatic igniter for intermittentlyigniting Waste gas at the top of a stack In various industrialapplications surplus or waste gases are discharged from tall stacks.When these gases are combustible it is a common practice to ignite themand permit them to burn at the top of the stack. Various means, such asspark devices, have been proposed and used for igniting gases at the topof such a stack. However none of these has proved completelysatisfactory and reliable and accordingly it is an object of the presentinvention to provide an improved means for automatically igniting gas atthe top of a stack.

Other objects of my invention are the provision of completely automaticmea-ns for igniting gas -which is discharged intermittently frorn astack, the igniter being controlled so that it is not eiective until thestack is purged of explosive mixtures; the provision of a gas igniterwhich automatically resets itself after each igniting cycle so that, ifthe gas supply to the stack is stopped and the ilame goes out, theigniter will automatically be ready to reignite the vgas when it againilows from the stack; and the provision of an automatic gas bleederigniter apparatus, particularly adapted for use with gas holders, whichis dependable, long-lived, and economical to install and maintain.

The above and other objects of my invention will appear from thefollowing description of one embodiment thereof, reference being had tothe accompanying drawings in Which:

Figure 1 is a diagrammatic layout of my igniter apparatus and controlhookup associated with a gas holder and bleeder stack therefor.

Figure 2 is a schematic Wiring diagram of the apparatus illustrated inFigure l.

Figure 3 is an enlarged fragmentary -view, taken on -line 3v3 of Fi-gure4, of the upper portion of a stack illustrating one of the igniterheating elements.

Figure 4 is a plan View, taken substantially on line 4 4 of Figure 3,but drawn on a somewhat larger scale.

Referring to Figure l, a gas holder is generally indicated at G. This isillustrated on a very small scale but is one of the common largetank-like structures comprising a fixed lower vessel 1 and a verticallymovable upper portion 2 which telescopes within the vessel 1 and risesand falls depending upon the amount of gas which enters the holder Gthrough the inlet pipe 3. A bleeder outlet pipe 4 extends to the bleederstack S and is provided with a bleeder valve 5 adapted to open or closethe connection from the gas holder G to stack S. Valve 5 is normallyheld closed as by a weight 5 and may be opened by lifting the arm 5".

The apparatus for opening valve 5 is also diagrammatically illustratedand is not drawn to scale. It includes a exible cable 6 attached to anarm 7 projecting from the top of the movable portion 2 of the Igasholder. This cable 6 passes around fixed pulleys 7 and 8 as indicatedand then makes a bend around the floating v e l 1C@ pulley 9 whichcarries a weight W. From pulley 9 cable 6 extends upwardly and overanother fixed pulley 10 and then down to an operating connection to thevalve operating arm 5". A fixed stop 11 is disposed in the path of themovable pulley 9 and prevents it from moving to an elevation higher thanthe stop 11 but does not interfere with rotation of the pulley 9.

When the movable portion 2 of gas holder G rises from the position shownthe weight W will be lifted but the portion 6 of cable 6 extendingbetween pulley 10 and valve arm 5" will not move because the forcerequired to lift the weight 5 is greater than that imposed by Weight W.When pulley 9 strikes the fixed stop 11 it cannot go any higher andfurther upward movement of the portion 2 of gas holder G will pull onthe cable 6 and cause corresponding upward movement of the portion 6' ofsaid cable. This will etect opening of the valve 5 and permit gas tobleed from the gas holder G to the stack S.

At the top of the stack S are a pair of heating or igniter elements Hand H' (one of which is shown in greater detail in Figure 3). Theseheating elements, as Will be later more fully described, compriseU-shaped electrical conductors, preferably made of corrosion resistantmaterial such as stainless steel. In the operation of my apparatus theseheating elements are electrically heated to an incandescent temperaturesufficient to ignite ygas emerging from the top of the stack. The meansfor controlling the heating of the elements H and H' is indicateddiagrammatically in Figure l and more in detail in Figure 2. As seen inFigure l, a suitable current supply is conducted to the apparatusthrough lines 12 and 13 which lead to the primary of a transformer 14. Alimit switch L is interposed in the line 15 which leads from one side ofthe secondary of transformer 14 to the control unit C While line 16leads from the other side of said secondary to control unit C. The mainheating current supply 12-13 is also conducted to the control unit Cthrough suitable conductors 12 and 13'.

The makeup and mode of operation of the control unit C and limit switchL will be fully described later with reference to Figure 2 and it 'willsuiice to point out here that limit switch L lis provided with. anoperating means, such as arm 19 which, as diagrammatically illustrated,has a forked end extending around the cable 6. A switch actuating block20 is secured to the cable 6 and, when the portion 6 thereof movesupwardly during or just after opening the valve 5 to the desired degree,the block 20 will engage the end of arm 19 and lift same to effectclosing of the limit switch L.

The result of closing the limit switch L upon opening of the bleedervalve 5 `will be to initiate the operation of the control unit C wherebygas is permitted to pass through the bleeder pipe 4 to the stack S for asulicient time to completely pur-ge the stack S of air and dangerousexplosive mixtures and then electrical connections are established fromthe power source to the resistance heating element H through Wires 21and 22 and to the resistance heating element H through wires 23 and 24.After the heating elements have reached ignition temperature and beenheld at that temperature for a period (for example two minutes)sufficient to ignite the gas emerging from the top of the stack, currentto the heating elements is automatically shut off. As long as valve 5 isopen and gas continues to be bled to the stack S it will burn, but ifthe supply to the gas holder G is cut ol or diminished and the upperportion 2 thereof moves downwardly the Valve 5 will be closed by Weight5. Such downward movement of the portion 2 of the gas holder will alsopermit the limit switch L to open, breaking the circuit to the controlunit C and permitting the mechanisms therein automatically toreset.themselvesforan- 'thereto are shown in detail.

other ignition cycle the next time the gas volume in holder G increasessuiciently to open valve 5 and close limit switch L.

The electrical connections and control mechanism of my improvedautomatic gas bleeder ignition apparatus are illustrated in theschematic wiring diagram of Figure 2. In this View the main currentsupply 12.-13 may be confsidered to be a 440 volt alternating currentsource. 'The control circuit transformer 14 has its primary connectedacross lines 12 and'13 and has leads 15 and 16 extending from itssecondary. As previously explained, limit switch L is interposed in line15 and is open (as seen in Figure 2) except when gas holder portion 2hais risen high enough to open the bleeder valve 5 and close limitswitch L. A repeat push button 25, the function of which will be laterdescribed, is also disposed in line 15 and is normally in closedposition as seen in Figure 2.

The first or circuit making timing relay R is connected across the lines15 and 16 by lines 15 and 16. It is provided with a normally opencontact arm 26 which, when open, breaks the circuit through lines 17, 18and 18' to the second or circuit breaking timing relay R.

This circuit breaking timing relay R is connected to the secondary ofthe control circuit transformer 14 on one side through lines 15, 27 and27 and on the other side through lines 16 and 17, contact arm 26 whenclosed, and lines 18 and 18. The contact arm 28 of timing relay R isnormally closed and completes and connection from line 29 to line 30.

Also incorporated in the control unit C is a contactor generallyindicated at M. This contactor M includes `a solenoid 31 which isconnected to the secondary of transformer 14 On one side through thelines previously referred to and lines -32 and 32', and on the otherside through the lines previously referred to and line 30. It will beunderstood that solenoid 31 will be energized only when both the contactarm 26 of timing relay R and contact arm 23 of timing relay R are intheir closed or circuit making positions. When solenoid 31 is energizedit is `adapted to actuate the contact member 33 of contactor M andcomplete the main heating circuit through lines 12' and 12 to line 34.

The primary 35' of heating element transformer 35 is connected acrossthe main heating current supply lines V34 and 13 by lines 36 and 36 andthe primary 37 of a similar heating element transformer 3'7 is connectedin parallel bythe lines 38 and 39. Interposed in line 36 is a variableresistance 40 and an ammeter 4l, and a similar variable resistance 42and ammeter 43 are interposed in line 38. The resistance heating elementH is connected to the `secondary 35" of transformer 35 by the lines 21and 22 and, in similar manner, the secondary 37" of heating elementtransformer 37 is connected to heating element H by the lines 23 and 24.

The function of lthe variable resistanceis 4th and 42 is to permitadjustment of the heating current applied to the heating elements H andH to the lowest value which will heat these elements to a ytemperaturesuicient dependably to ignite the gas at the top of the stock. ln orderto increase the life of the heating elements H and vH it is desirable tooperate them at the lowest temperature which will achieve the desiredresults and it is for this reason that the variable resistances 4@ and42 and ammeters 41 and 43 are provided. By arranging the heatvingelements H and H in parallel one may burn out, or otherwise fail,without interfering with the operation of the other. The transformers 35and 37 are provided to furnish the desired low voltage, high amperagecurrent to the heating elements H and H.

In Figure 3 and 4 the heating element H', its mounting on `the stack S,and the electrical connections leading As explained above, the `elementH is of generally hairpin or loop shape having its .closed upper end 45bent outwardly to overhang the Ledge of the `stack S. The lower ends ofelement H are secured, as by welding, to supporting brackets 46 and 47.Bolts 48 and 49 extend through the stack S and serve to clamp -thebrackets 46 and 47 respectively in position. This clamping action iseffected by Athe nuts 50 and 51 and insulating washers 52 and 53, andinsulating bushings 54, electrically insulate these parts from the metalstack S. Current is conducted to thetbolts 48 and 49 by bus bars 55 and56, which are secured on the outerends of bolts 4S and 49 by nuts 57 and58. As indicated in Figure '3 these nuts may be welded to the adjacentbolt and bus bar and the heads of the bolts 48 and 49 may be welded tothe brackets 46 and 47 in order to insure proper electrical connectionand to prevent loosening of the parts.

The sequence of operation of the entire mechanism described above willnow be explained:

When the movable portion 2 of the gas holder G rises to a predeterminedvalue:the valve 5 will be opened and the limit switch L will be closed.When this occurs the first timing relay R will be activated or set intoaction. This relay may be any one of several well known types andaccordingly its detailed mechanical structure will not be described. Itis so arranged that when energized by the closing of switch L a timedelay mechanism starts to function and the Contact arm 26 will not bemoved from its open position (seen in Figure 2) to closed position untilafter a predetermined time delay, for example three minutes, hasoccurred. This time delay is adjusted to be such that the gas enteringthe stack S through the bleeder pipe 4 will have completely purged thestack of air before contact arm 26 is closed.

When the time delay period of relay R ends the contact arm 26 will beclosed, completing the control circuit to the second timing relay R andalso to the contactor M because the arm 28 of relay R is normallyclosed. As soon as contactor M is energized the contact member 33 ismoved to complete the circuit in line 1212 and the main current supplywill then be connected to the transformers 35 and 37 and the heating origniter elements H and H will immediately start to warm up.

As it takessome time, for example about seconds, for the heatingelements H and H to reach gas ignition temperature, and as it is desiredto leave the heating elef ments Hand H at their igniting temperature forperiod suicient to insure ignition of the gas emerging from the stack S,the second timing relay R is so arranged that its contact arm 2S remainsin closed or circuit making position (as seen in Figure 2) untilsuflicient time has elapsed to insure ignition of the gas. This may be,for example, three and one half minutes. At the end of this time thetiming relay R operates to move the contact arm Z8 out of its circuitmaking position and to break the circuit between lines 29 and 30. Thisresults in the immediate de-energizing of the contactor M and theimmediate movement of its contact member 33 into open position. Whenthis occurs the main heating circuit to the heating elements H and H' isbroken and they immediately cool down to normal temperature.

After the above described cycle and for so long as the limit switch L isheld closed and the valve 5 is open and discharging gas into the stackS, the first timing relay R will be energized and its contaotor 26 heldclosed. This will result in the second timing relay R also beingenergized and its contact arm 28 held open. However, when the supply ofgas in the gas holder diminishes and the upper movable portion 2 movesdownwardly, the limit switch L will open and the valve 5 will close at apre-determined point. When the valve 5 closes the gas supply to thestack is shut oif and the llame at the top goes out. When limit switch Lis opened relay R is deenergized and the Contact arm 26 immediatelymoves to its open position. The second timing relay R is alsoimmediately de-energized when the limit switch L is opened and itscontact arm moves immediately from open posif assaasr tion back into itsnormal closed position as seen in Figure 2.

As the contacter M has previously been de-energized and has opened thecircuit in lines 12' and 12, all three units R, R and M are now againready for another gas igniting cycle. This will occur in the mannerdescribed above as soon as the upper portion 2 of the gas holder G againmoves upwardly suciently to open the valve 5 and close the limit switchL.

From the above it will be observed that my improved gas ignitingmechanism is entirely automatic in its operation and will effectivelyand safely ignite gas at the top of a stack each time that gas isdischarged into the stack.

A repeat push button 25 is provided in the line 15 in order that the gasmay be reignited if, due to extremely high winds or other unusualcircumstances, the flame at the top of the stack is extinguished whilegas is still owing into the stack. In such event it is only necessary tooperate the push button 25 to break the control circuit through line 15.This will result in the same sequence of events as happens when thelimit switch L is opened upon downward movement of the gas holder. Afterthe control circuit has been broken by manually moving the push button25 the units R, R and M will all immediately be reset and then, uponrelease of push button 25 and cornpletion of the control circuit throughline 1S, the elements H and H' will be heated to ignition temperatureand the gas will be lit again. Push button 25 is also available fortesting when desired.

Although I have described the illustrated embodiment of my invention inconsiderable detail it will be understood that variations andmodications may be made in the form and arrangement of the variouselements making up my improved apparatus. For example, the timing relaysshown and described in the control circuit are of the type which are setinto action or activated when the control circuit to them is closed toenergize the relay mechanism. As is well understood in the art, timingrelays, contactors, etc., may be arranged to be set into action oractivated when the control circuit thereto is broken to de-energize themechanism. Accordingly, the terms activate and de-activate as used inthe speciiication and claims are intended to include both closing andopening of the circuit in question. Accordingly, I do not wish to belimited to the exact equipment herein shown and described but claim asmy invention all embodiments thereof coming within the scope of theappended claims.

I claim:

1. In gas igniter apparatus, a stack having an open discharge end and animperforate wall adjacent said open discharge end, an electricalresistance heating element having spaced ends and a closed loop portiontherebetween, spaced supports for said ends of said element on theinside of said stack adjacent said open discharge end, and conductorsextending through the wall of said stack from said supports, the spacedends of said heating element being entirely within and closely adjacentto the inner surface of said imperforate wall and the closed loopportion of said heating element extending outwardly beyond said opendischarge end of said stack and being bent outwardly into verticallyover-hanging relation to the periphery of said discharge end of saidstack.

2. Gas bleeder igniter apparatus for purging a stack of air and thenigniting gas discharged at the top of the stack comprising, a stackhaving a top end opening to the atmosphere, a valve for controlling theow of gas to the stack, means for opening said valve, an electricalresistance igniter element of loop form disposed at and having itsclosed end extending above the top end of the stack adjacent and inoverhanging relation to the periphery thereof, said igniter elementhaving spaced end portions entirely within and closely adjacent to theinner surface of said stack, said stack being imperforate adjacent saidVigniter element, electrical connections from a main current supply tosaid igniter element, an electrically operated contacter having an openposition and a closed position and adapted when closed to complete saidelectrical connections from said main current supply to said igniterelement, a control circuit including a source of control current andsaid contacter, main switch means in said control circuit, meansactuated by said valve opening means for closing said main switch meanswhen said valve is opened, a time delay relay connected in said controlcircuit to be energized upon closing said switch means, said time delayrelay being adapted to close said control circuit and energize saidelectrically operated contactor at a predetermined time after said relayis closed, said contacter being adapted when energized to close andcornplete said connections from said main current supply to said igniterelement, a second time delay relay connected in said control circuit tobe energized upon closing of said control circuit by said first namedtime delay relay, said second time delay relay being adapted to opensaid control circuit and de-energize said electrically operatedcontactor at a predetermined time after said contacter has beenenergized, and manually operable switch means for temporarily openingand then closing said control circuit independently of said main switchmeans in order to effect repeat operation of the igniter cycle when saidmain switch is closed.

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